Temporomandibular Joint Flashcards
What is bruxism?
Grinding teeth when sleeping
lateral pterygoid muscle helps….
comes from….
helps protude the madibule muscles
running laterall attached to the TMJ joint, to the condylar process, anterorior it is attched to the pterygoid plates of the sphenoid bone
What are the movements of the TMJ generally produced by?
Muscles of mastication Hyoid muscles
Massater does what….
comes from..
elevates the mandibule
zygomtic process/zygomatic bone and inserting into the ramus of the mandible
What are the articular surfaces of the TMJ lined with?
Fibrocartilage
Which muscles carry out protrusion and retraction of the TMJ?
Protrusion - lateral pterygoid Retraction - geniohyoid and digastric
Temporalis does what
if mandible is protruded
inserts into
come from
elevates the mandibular,
it will pull it back in coroniod process attached to mandible,
coronoid process
coming from temporal region and passes deep to the bones of the zygomatic arch
what bones does the 2 mandibular process articulate with
condylar with temporal bone and coronoid process with zygomatic complex
What can be damaged in a dislocation of the TMJ?
Facial and auriculotemporal nerves
Function of the superior and inferior cavities?
Inferior - rotation of the jaw for the first few mm of opening the jaw Superior - translocation of the head of the mandible (moving anteriorly and inferiorly) for opening of the jaw the rest of the way
Where does the sphenoidmandibular ligament run from and to?
From the sphenoid spine to the mandible
Which muscles carry out elevation and depression of the TMJ?
Depression - gravity. If there is resistance, digastric, geniohyoid and mylohyoid muscles Elevation - temporalis, masseter, medial pterygoid muscles
What happens in a dislocation of the TMJ?
Head of mandible slips out of the mandibular fossa and pulled anteriorly over the articular tubercle - patient unable to close their mouth
Where does the stylomandibular ligament run from and to?
Thickening of the fascia of the parotid gland
What articulates at the TMJ?
Mandibular fossa and head of mandible with the articular tubercle from the squamous part of the temporal bone
What are the movements of the TMJ?
Protrusion and retraction Elevation and depression
Whats the two process of the mandible
condylar process and coronoid process
Why are posterior dislocations of the jaw rare?
Need to overcome the postglenoid tubercle and the strong intrinsic lateral ligament
medial pterygoid muscle comes from…
holds the manibule in place, evelvate the manduble and for protudtion attched to the angle/ramus of the madible, running at a angle towards the pterygoid plates of the sphenoid bone
What separates the articular surfaces of the TMJ so that they never come into contact?
Articular disk Splits it into two synovial joint cavities, each lined by a synovial membrane
How can dislocation of the TMJ occur?
Blow to the side of the face Yawning, large bite
Name the three ligaments of the TMJ and give each one’s function
Lateral aka temporomandibular - prevent posterior dislocation Sphenomandibular - prevent inferior dislocation Stylomandibular - supports the weight of the joint along with the facial muscles
PICTURE Where does the lateral ligament run from and to?
what does it do?
thickened lateral portion of the capsule, runs from the begining of the articular tubule to the mandibular neck
passive support, prevent postier dislocation of the joint
Function of the stylomandibular ligament?
Separated the parotid gland from the submandibular gland
Protrusion is caused by….
it does this by
Attched to ……….. posteriorally and ……. anteriorly
Theses muscles can be seprated into
bilateral contraction of the lateral pterygoid.
pulling the mandibule condyner process anteriorlly
TMJ( condyler process)/ pterogoid plates of the sphenoid bone
Inferior lateral pterygoid and superior lateral pterygoid
Opening –
inferior head of lateral pterygoid, anterior digastric, mylohyoid. Opening is also controlled by eccentric contraction of the closing muscles against gravity. The articular disc moves forward with the condyle as it glides forward, effectively extending the superior articular surface of the mandibular fossa.
muscle for Closing mouth–
masseter, anterior and middle temporalis, medial pterygoid, superior head lateral pterygoid.
Capsule -
The capsule is a fibrous membrane that surrounds the joint and attaches to the articular eminence, the articular disc and the neck of the mandibular condyle.
what is the Articular disc -
what does it articulate with….
what does the disk do with the joints
The articular disc is a fibrous extension of the capsule that runs between the two articular surfaces of the temporomandibular joint.
The disc articulates with the mandibular fossa of the temporal bone above and the condyle of the mandible below.
The disc divides the joint into two sections, each with its own synovial membrane.
how is Retrodiscal tissue unlike the disc
clincally this means
Unlike the disc itself, the retrodiscal tissue is vascular and highly innervated.
As a result, the retrodiscal tissue is often a major contributor to the pain of Temporomandibular Disorder (TMD), particularly when there is inflammation or compression within the joint[2]
Name the parts of the TMJ
Name the Ligmaments of the TMJ
muscle resposible for Retrusion –
middle and posterior temporalis, possibly helped by deep posterior portion of masseter
muscle respoabile for Laterotrusion (side to side) –
ipsilateral middle and posterior temporalis, contralateral inferior head lateral pterygoid.
Name the TMJ muscle lateral view
Name the ptergoid muscle
inferior view of the TMJ
